EXCEED THE SPACE PROVIDED. It is proposed to continue to operate and extend the capabilities of the Rockefeller University Biotechnology Research Resource. Emphasis will be placed upon the mass spectrometry (MS) of proteins and on developing proteomic tools for dissecting cellular function. The major subdivisions of the Resource activity will be basic research in MS, collaborative research on challenging biological problems, high-level bioanalytical service, and dissemination of newly developed technologies to the biomedical community in the USA. Basic research will involve (1) the development of improved instrumentation for rapid, sensitive MS/MS of peptides for protein identification, (2) the development of novel instrumentation for ultra-high sensitivity detection and characterization of phosphopeptides, (3) methods for improving MS sensitivity to the sub-atomole level, (4) improved methods for studying protein interactions, (5) improved methods for studying protein phosphorylation, (6) development of a toolset for differential proteomics, (7) improved MS tools for atomic resolution structure analysis of proteins, and (8) informatics tools utilizing MS data for the analysis of the proteome. Collaborative research will involve studies of signaling and control viaprotein pbosphorylation (e.g., cystic fibrosis transmembrane regulator function;identification of novel substrates for protein phosphatase 1; NFAT kinases), definition ofprotein machines and complexes (e.g., yeast nucleocytoplasmic transport machinery; the vertebrate nuclear pore complex; the Trypanasoma brucei nuclear pore complex; glycopeptide export from the mammalian ER; bell cycle control in budding yeast; molecular genetics of trypanosome antigenic variation; eukaryotic replication machines), protein interactions in mouse and man (e.g., cell- specific proteins in mouse brain; eukaryotic transcription complexes; the p53-mdm2 complex; Stat proteins; protein components of human telomeres), 'protein structure and function (e.g., ion channels, G protein-coupled receptors; RNA polymerase II); structural'genomics, protein modifications by 'SUMO', the WW domain network in yeast, yeast prions, the obesity hormone leptin, opioid receptor systems in addiction and analgesia, and identifying proteins in the erythrocyte plasma membrane that are encoded by the malaria parasite.